WO2011036053A1 - Dispersion of a water-soluble polymer in a liquid medium - Google Patents

Abstract

The present invention relates to a dispersion of a water-soluble polymer in a non-aqueous liquid medium. The non-aqueous medium includes a large amount of a surfactant.

Description

 Dispersion of a water-soluble polymer in a liquid medium

The present invention relates to a dispersion of a water-soluble polymer in a non-aqueous liquid medium. The non-aqueous medium comprises a significant amount of surfactant.

Water-soluble polymers, especially hydrocolloids such as optionally modified guars are additives used in various industries for various functions. They can be used in particular as rheological agents because they increase the viscosity when they are solubilized in water. In the phytosanitary field they are for example used as anti-drifting and / or anti-rebound agents. For this purpose they are most often added extemporaneously (usually by the farmer) by mixing in a tank with active agents and / or other additives to be spread on a field, usually with dilution in water. . These extemporaneous uses are called "tank mix" in English. The mixture is then spread, for example pulverized, on a field.

 There is a need for products intended to be diluted and / or formulated, especially for complex concentrated ingredients, combining several functions and practical use. In particular, there is a need for products combining functions of water-soluble polymers, for example anti-drifting and / or debouncing agent functions and surfactant functions (known to those skilled in the art), while by presenting a practical and / or economic use.

 US 6146570 discloses water-soluble polymer granules comprising a nonionic surfactant. There is a need for liquid dispersions, of more practical use. There is also a need for products effectively combining several functions, including effective amounts of surfactant.

 WO 2006/014348 discloses aqueous spray compositions comprising a water-soluble polymer and surfactants. The polymer is mixed in solid form with the surfactant extemporaneously (tank-mix). There is a need for simpler processes, particularly involving liquid dispersions, of more practical use. There is also a need for products effectively combining several functions, including effective amounts of surfactant.

US 6465553 discloses dispersions of water-soluble polymers in non-aqueous liquid media comprising a mixture of polyethylene glycol compounds. The quantities of polymers are relatively large (more than 20% by weight). There is a need for different dispersions, which may include less polymer. There is also a need for products effectively combining several functions, including effective amounts of surfactant.

 US 2003/0203821 discloses suspensions in nonaqueous liquid media comprising a polyethylene glycol, a dispersing agent such as calcium stearate, and a polymeric suspending agent. The amounts of polymers are relatively large (more than 20% by weight). There is a need for different dispersions, which may include less polymer.

 US 4176107 discloses suspensions in non-aqueous liquid media comprising a polyethylene glycol and a surfactant. The amounts of polymers are relatively large (more than 20% by weight). There is a need for different dispersions, which may include less polymer.

The invention meets at least one of the above-mentioned needs by providing a dispersion of particles of a water-soluble polymer in a non-aqueous liquid medium, comprising:

a) from 0 to 10 parts of water

b) from 1 to 20 parts, preferably from 5 to 15 parts of a water-soluble polymer

c) from 0.5 to 5 parts, preferably from 1 to 3 parts of a heavy polyethylene glycol, with an average molecular weight greater than or equal to 6000 g / mol and preferably less than or equal to 500000 g / mol,

d) from 80 to 99 parts, of a liquid medium comprising:

 d1) optionally a light polyethylene glycol of average molar mass less than or equal to 1000 g / mol, alone or mixed with up to 20% by weight of glycerol

 d2) a nonionic surfactant, preferably ethoxylated and / or propoxylated

 the ratio by weight between d2) and d1), if d1) is present; being 1/2 to 99/1, preferably 40/60 to 80/20.

e) optionally other additives.

 It has surprisingly been found that it is possible to present water-soluble polymer dispersions in media comprising substantial amounts of surfactants. This can make it possible to simplify the downstream blending operations by the user and / or to simplify transport and / or storage.

The dispersion of particles of the invention may constitute a complex concentrated ingredient particularly useful especially in the field of agriculture. It can thus be used as an extemporaneous ingredient ("tank mix" in English), especially in as an anti-drifting and / or anti-rebound agent. The dispersion makes it possible in particular to combine the functions of anti-drifting and / or anti-rebound agent and the functions related to the surfactant.

The invention also relates to a process for preparing the dispersion. The invention also relates to the use of the dispersion as an extemporaneous adjuvant of a dilute phytosanitary composition intended to be applied on a field. The invention also relates to a method for applying a phytosanitary composition to a field, comprising

 a step of mixing in a reservoir of the dispersion, of water and of at least one phytosanitary product, where appropriate in the form of a concentrated phytosanitary composition, so as to obtain a diluted phytosanitary composition,

 an application step on the field of the diluted phytosanitary composition.

Definitions

 In the present application, the quantities indicated in parts are quantities by weight. In the present application, unless otherwise stated, the amounts by weight are amounts by weight of dry matter (as opposed to amounts by weight of ingredients "as is").

 In the present application, the term "water-soluble polymer" means a polymer that is soluble in water at a concentration of 0.1% by weight, preferably 1%, for example at a concentration of 0.6 g / l.

 In the present application, unless indicated otherwise, the particle sizes are given in average diameter, typically measured by dry-sided particle size, for example determined using the Malvern® Sizer.

Dispersion

The water-soluble polymer b) is typically dispersed in the liquid medium d) in particulate form. In general, the dispersion is obtained from a powder of the polymer, mixed in the liquid medium, which optionally comprises other compounds in addition. The particles of the powder may typically have a particle size of 1 to 500 μηι, for example 1 μηη at 10 μηι, or of more than 10 μηη at 40 μηη or of more than 40 μηη at 80 μηι, or more than 80 μηι. μηη to 100 μηι, or from more than 100 μηη to 200 μηι, or from more than 200 μηη to 300 μηη or from more than 300 μηη to 400 μηι, or from more than 400 μηη to 500 μηι. The particles in the dispersion have a size (eg observed under a microscope) substantially similar to that of the powder. It is possible, however, that the particles undergo some swelling in the liquid medium. The particle size in the liquid medium is generally not greater than 10 times, preferably not more than 5 times the size of the particles in powder form. Thus, the particles in the dispersion may have a size of 1 to 500 μηι, for example 1 μηη at 10 μηι, or more than 10 μηη at 40 μηη or more than 40 μηη at 80 μηι, or more than 80 μηη at 100 μηι, or from more than 100 μηη to 200 μηι, or from more than 200 μηη to 300 μηη or from more than 300 μηη to 400 μηι, or from more than 400 μηη to 500 μηι. a) water

 The dispersion can be substantially free of water or comprise relatively modest amounts of water. The presence of water may be experienced as an impurity or by-product of the dispersion ingredients or as a dilution medium for the dispersion ingredients. The composition comprises at most 10 parts by weight of water, preferably at most 5 parts, by weight of water. b) water-soluble polymer

 The water-soluble polymer may be a synthetic polymer or a polymer of natural origin, optionally modified.

 Since it is a dispersion, the water-soluble polymer is substantially insoluble (solubility less than 10% by weight, preferably less than 1% by weight) in the liquid medium d). Preferably it is substantially insoluble in d1) and d2).

According to one embodiment, the water-soluble polymer is a polyhydroxylated polymer or copolymer chosen from polysaccharides of animal, vegetable or bacterial origin, or also polyvinyl alcohol, polyphenol alcohols, or their derivatives. The polysaccharides may be used in an ionic or nonionic form. Xanthan gum, succinoglycans, gum arabic, carrageenans, alginates are representative elements of anionic polysaccharides, cationic derivatives of starch can also be mentioned. As regards nonionic polysaccharides, mention may be made in particular of galactomannans, such as guar gum or its derivatives such as hydroxypropyl guar, locust bean gum, soluble starch and its nonionic derivatives, cellulose and its derivatives. carboxyalkyl, hydroxyalkyl, for which the alkyl portion has 1 to 4 carbon atoms. As polyhydroxylated polymers or copolymers, and as indicated previously, polyvinyl alcohol, polyphenol alcohols or their derivatives are suitable. Among the possible derivatives, there are polyetherified (co) polymers, such as those whose ether portion is a C 1 -C 6 alkyl radical. -C "8 or C 6 -C 8 aryl, alkylaryl or arylalkyl, the alkyl and aryl parts being defined above.O may also be suitable as derivatives, (co) polymers bearing at least one radical ionic (anionic, cationic, zwitterionic, amphoteric). By way of anionic radical, mention may be made without intention of being limited to sulphonate, sulphate, carboxylate, phosphate or phosphonate radicals; by way of example of a cationic radical, mention may be made of quaternary ammonium radicals such as N (R) 4 ⁺ with R, which may be identical or different, representing a hydrogen atom or a C 1 -C 6 alkyl radical; -C6; the zwitterionic and amphoteric radicals corresponding to the combination of the two types of radicals mentioned above. It is pointed out that the polyphenol-type (co) polymers are natural substances, which can, in particular, be extracted from certain plants such as coffee trees, tea plants.

 According to another embodiment, the water-soluble polymer is chosen from copolymers obtained from alkylene oxide and from at least one saturated or unsaturated monomer, comprising one or more carboxylic groups, in an acid form, of alkali metal salts, of ester or of amide, or comprising an amino or nitrile group, or comprising a grouping

heterocyclic nitrogen containing. As saturated or unsaturated monomer

comprising one or more carboxylic groups, mention may be made of C3-C10 mono- or di-acids, and their derivatives in the form of alkaline, alkaline-earth metal or ammonium salts (N (R) 4 ^{+ type} , with R representing hydrogen or a C 1 -C 6 alkyl radical, in the form of mono- or di-esters with at least one C 1 -C 6 alcohol; 2, more particularly in C- | -C8, and their N-alkylated derivatives, or in the form of amide. For example, acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid, acrylamide, methacrylamide, N-methylolacrylamide, N -methylolmethacrylamide, as well as the acid salts or monodiodes obtained from the following acids and alcohols: methanol, ethanol, propanol, n-butanol, isopropanol, isobutanol, ethyl-2-hexanol, for example non-limiting illustration. The amino acids or their salts or esters are suitable for carrying out the invention, such as aspartic acid.

 Also suitable are monomers of the vinyl ester type of C2-C-10 carboxylic acid, such as, for example, vinyl acetate, vinyl versatate,

vinyl propionate. With regard to the saturated or unsaturated monomers comprising an amino, amido or nitrile group, mention may be made of the monomers whose hydrocarbon chain is C 3 -C 12. As saturated monomer, mention may be made of acrylonitrile, methacrylonitrile, vinylpyridine, vinylpyrrolidone,

vinylimidazole, aminoalkyl (meth) acrylates, such as

dimethylamino (meth) acrylate, ditertiobutylaminoethyl (meth) acrylate,

dimethylamino (meth) acrylamide, ditertiobutylaminoethyl (meth) acrylamide. According to another embodiment, the water-soluble polymer is chosen from plant polymers such as alkali metal, alkaline-earth metal or ammonium lignosulfonate.

According to another embodiment, the water-soluble polymer is chosen from polymers obtained from at least one saturated or unsaturated monomer, comprising one or more carboxylic groups, in the form of an acid, of alkali metal salts, of ester or amide, or comprising an amino or nitrile group, or comprising a nitrogen-containing heterocyclic group, as well as copolymers obtained by reacting at least one of the aforementioned monomers with at least one second monomer hydrocarbon bearing one or more ethylenic unsaturations. As a saturated or unsaturated monomer comprising one or more carboxylic groups, mention may be made of C 3 -C 10 mono- or di-acids and their derivatives in the form of alkali metal, alkaline-earth metal or ammonium salts (type N (R) 4 ⁺ , with R representing hydrogen or a C 1 -C 6 alkyl radical, in the form of mono- or di-esters with at least one C 1 -C 12 alcohol, more particularly C 1 -C 6 alkyl; -C8, and their N-alkylated derivatives, or in the form of amide. For example, acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid, acrylamide, methacrylamide, N-methylolacrylamide, N -methylolmethacrylamide, as well as the acid salts or the monodi-esters obtained from the following acids and alcohols: methanol, ethanol, propanol, n-butanol, isopropanol, isobutanol, ethyl-2-hexanol, as non-limiting illustration. The amino acids or their salts or esters are suitable for carrying out the invention, such as aspartic acid. Also suitable are monomers of the vinyl ester type of C2-C10 carboxylic acid, such as, for example, vinyl acetate, vinyl versatate, vinyl propionate. As regards the saturated or unsaturated monomers, comprising an amino, amido or nitrile group, mention may be made of the monomers whose hydrocarbon chain is C 3 -C 12 as a saturated monomer, mention may be made of acrylonitrile and methacrylonitrile , vinylpyridine, vinylpyrrolidone, vinylimidazole, aminoalkyl (meth) acrylates, such as dimethylamino (meth) acrylate,

ditertiobutylaminoethyl (meth) acrylate, dimethylamino (meth) acrylamide, ditertiobutylaminoethyl (meth) acrylamide. Each of the abovementioned monomers can be used in the form of ionic derivatives, that is to say comprising at least one sulphonic function, for example, in acid or salified form in whole or in part. With regard to the second type of monomer, used in

In combination with the first cities, mention may be made without intention of limiting it to C2-C12 hydrocarbon monomers, whether or not comprising an aryl radical, and furthermore having at least one ethylenic unsaturation. Among other things, butadiene, isobutylene, diisobutylene, styrene, vinylstyrene, alphamethylstyrene, vinyltoluene. Particularly advantageous polymers include polymers such as polyacrylate; polymethacrylate; the

polyvinylpyrrolidone; polyacrylamide; polyaspartate. Mention may also be made of copolymers of maleic acid or anhydride with isobutylene or diisobutylene; pyrrolidone and vinyl acetate. Note that depending on the nature of the compound used, the aqueous medium may be added for example base or acid, so as to have its pH adjusted so that the solubility of said compound meets the criteria mentioned above.

The water-soluble polymer may be chosen from polymers that can be used as anti-drifting and / or anti-rebound agents in the phytosanitary field. As such agents of synthetic origin are cited polymers based on acrylamide or vinylpyrrolidone. As such agents of natural origin, mention is made of celluloses and their chemical modification products such as carboxymethylcelluloses, as well as guars and their chemical modification products such as hydroxypolylated or hydroxybutyl guars. Lecitines and their chemical modification products are also mentioned. The molar mass of the water-soluble polymer can typically from 100000 g / mol to

10,000,000 g / mol, for example from 500,000 g / mol to 5000000 g / mol, for example from 500000 to 1000000 g / mol or from 1000000 to 1500000 g / mol, or from 1500000 to 2000000 g / mol or from 2000000 to 3000000 g / mol g / mol or from 3000000 to 4000000 g / mol or from 4000000 to 5000000 g / mol. The molar mass is typically the average molar mass by weight, determined not GPC.

The water-soluble polymer may especially be a chemically modified guar, for example by hydroxyalkyl groups, preferably hydroxypropyl or hydroxbutyl. Guar can alternatively or additionally be modified by groups

carboxymethyl. The degree of substitution DS (representative of the amount of chemical modification) of the guar can in particular be from 0.1 to 2, for example from 0.2 to 1.5. The degree of substitution is the number of hydroxyl groups of the guar substituted by modification groups, per unit of guar monosaccharide. This is a parameter for modified sites.

An example of the definition of DS substitution degree and molecular modification rate (MS) is given in the figure below.

 For guar hydroxypropyl MS = 4/3 = 1, 33 and DS = 3/3 = 1.

Products that can be used as water-soluble polymer are commercially available, in particular under the references Jaguar® HP, Rhodia Agrho® DR 2000 or Agrho® DEP775, Rhodia. The products of Rhodia Jaguar® HP 8 or Jaguar® HP 120 are mentioned. C) Polyglycol heavy glycol

 The light polyethylene glycol has an average molecular weight (in number or weight) of less than 6000 g / mol. The average molar mass may for example be between 8000 g / mol and 15000 g / mol. Such compounds are commercially available.

 While not wishing to be bound by any theory, it is believed that heavy polyethylene glycol can help stabilize the dispersion and prevent or slow down sedimentation. In the dispersion the heavy polyethylene glycol may in particular be in the form of often semi-crystalline particles, for example in the form of needles creating a network structuring the liquid medium. d) liquid medium

The liquid medium comprises d1) optionally light polyethylene glycol (optionally mixed with glycerol) and d2) a nonionic surfactant. The ratio by weight between d2) and d1), if d1) is present, is from ½ to 99/1, preferably from 40/60 to 80/20. According to a particular embodiment, there is more surfactant than polyethylene glycol. d1) light glycol glycol The light polyethylene glycol has an average molecular weight (number or weight) of less than 1000 g / mol. The average molar mass may for example be from 100 g / mol to 500 g / mol. Such compounds are commercially available.

 According to one embodiment, a portion of the light polyethylene glycol is substituted with glycerol. The amount of glycerol may, for example, be up to 20% by weight (relative to the mixture of light polyethylene glycol + glycerol). It can for example be 10 to 20%.

 In a particular embodiment, the light polyethylene glycol is absent. In one embodiment it is present in a small quantity such that the ratio d2) / d1) is greater than 99/1. d2) Nonionic surfactant

 Nonionic surfactants are known to those skilled in the art. It is preferably ethoxylated and / or propoxylated nonionic surfactants, also known.

 Liquid nonionic surfactants are preferably used at room temperature (typically 20 or 25 ° C).

 Some surfactants have wetting or bioactivation properties.

Such surfactants may be preferred.

 The ethoxy units (often denoted OE as they can be obtained from Ethylene Oxide) and / or propoxy (often denoted OP because they can be obtained from Propylene Oxide) can typically be in average number of 2. to 100. In the nonionic surfactant comprises both ethoxy and propoxy units, their distribution can be statistical or sequenced (in blocks), for example of type OE then OP or OP then OE, or OP then OE then OP or OE then OP then OE.

 As examples of nonionic surfactants, mention may be made, without intention of being limited thereto:

- polyalkoxylated (ethoxylated, propoxylated, ethopropoxylated) substituted by at least one alkyl radical C ₄ -C ₂ o, preferably C ₄ -C _2, or substituted by at least one alkylaryl radical in which the alkyl part is Ci-C ₆ . More particularly, the total number of alkoxylated units is between 2 and 100. By way of example, mention may be made of polyalkoxylated mono-, di- or tri (phenylethyl) phenols, or polyalkoxylated nonylphenols. Among the ethoxylated and / or propoxylated, sulphated and / or phosphated di- or tristyrylphenols, mention may be made of ethoxylated di- (1-phenylethyl) phenol, containing 10 oxyethylenated units, ethoxylated di (1-phenylethyl) phenol. , containing 7 oxyethylenated units, sulfated ethoxylated di- (1-phenylethyl) phenol, containing 7 oxyethylenated units, ethoxylated tri (1-phenylethyl) phenol, containing 8 oxyethylenated units, tri (1-phenylethyl) ethoxylated phenol, containing 16 oxyethylene units, ethoxylated tri (1-phenylethyl) phenol sulfated, containing 16 oxyethylene units, ethoxylated tri- (1-phenylethyl) phenol, containing 20 oxyethylene units, ethoxylated tri- (1-phenylethyl) phenol posphated, containing 16 oxyethylenated units.

alcohols or C ₆ -C ₂ fatty acids, optionally polyalkoxylated (ethoxylated, propoxylated, ethopropoxylated). In the case where they are present, the number of alkoxylated units is between 1 and 60. The term ethoxylated fatty acid includes both the products obtained by ethoxylation of a fatty acid with ethylene oxide and those obtained by esterification. of a fatty acid with a polyethylene glycol.

 polyalkoxylated triglycerides (ethoxylated, propoxylated, ethopropoxylated) of vegetable or animal origin. Thus triglycerides from lard, tallow, peanut oil, butter oil, cottonseed oil, linseed oil, olive oil, are suitable. palm oil, grape seed oil, fish oil, soybean oil, castor oil, rapeseed oil, coconut oil coconut oil, and comprising a total number of alkoxylated units of between 1 and 60. The term ethoxylated triglyceride is intended both for the products obtained by ethoxylation of a triglyceride by ethylene oxide and those obtained by ethoxylation of a triglyceride with ethylene oxide. by trans-esterification of a triglyceride with a polyethylene glycol.

 the ethoxylated and / or propoxylated terpenes

 block copolymers of ethylene oxide and C3-C10 alkylene oxide,

- sorbitan esters, polyalkoxylated (ethoxylated, propoxylated, ethopropoxylated), particularly cyclized sorbitol esters of fatty acids of C10 to C _20, such as lauric acid, stearic acid or oleic acid, and comprising a number total of alkoxylated units of between 2 and 50.

 Some particularly useful nonionic surfactants are:

ethoxylated and / or propoxylated fatty alcohols,

 ethoxylated and / or propoxylated fatty acids,

 non-alkoxylated fatty acids,

 block copolymers of polyethylene oxide and poly (propylene oxide)

ethoxylated and / or propoxylated di and / or tri styrylphenols, or

the ethoxylated and / or propoxylated terpenes,

 - their mixtures or associations.

It is mentioned that surfactants of the terpene type ethoxylated and / or propoxylated are described in particular in WO 96/01245, WO 98/28249, WO 01/12765, and are marketed by Rhodia under the name Rhodoclean®. Advantageously, said polyethoxylated and / or polypropoxylated terpene nonionic surfactant, preferably polyethoxylated and polypropoxylated, the ethoxy and propoxy units being distributed in random form or in sequential form.

 Preferably, said nonionic surfactant is a polyalkoxylated terpene corresponding to the following formula (III):

ZX- [CH (R5) -CH (R6) -O] _n - [CH2CH2-0] p- [CH (R5) -CH (R6) -O] q-R7 (III) in which formula

 Z represents a bicyclo [a, b, c] heptenyl or bicyclo [a, b, c] heptyl radical, with

 a + b + c = 5

 a = 2, 3 or 4,

 b = 2 or 1

 c = 0 or 1,

 said radical being optionally substituted by at least one alkyl radical of C- | -C6, and comprising a skeleton Z chosen from those indicated below, or corresponding skeletons, devoid of double bond:

at)

d)

d)

boy Wut)

X represents -CH2-C (R 0) (R 0- or -O-CH (R ') -C (R' 0-) in which:

R, R, R 'and R', which are identical or different, represent hydrogen or a hydrocarbon radical, saturated or unsaturated, linear, branched or cyclic, in C- | C22. preferably C- | -C6 ^■ R5 and R6, which may be identical or different, represent hydrogen or a hydrocarbon radical, saturated or unsaturated, linear, branched or cyclic, in C- | -C22, with the proviso that at least one of R5 OR R6 is different from hydrogen;

 R7 represents hydrogen, a hydrocarbon radical, saturated or unsaturated, linear, branched or cyclic, aromatic or not, in C- | C22. optionally substituted (for example with an OH group);

 n, p, q and are integers or not, greater than or equal to 0,

 n + p + q> 1, preferably from 2 to 200, preferably from 5 to 50. Preferably Z or ZX- corresponds to (6,6-dimethylbicyclo [3, 1, 1] hept-2-ene-2 ethanol), also referred to as "NOPOL".

Preferably, n, p and q are chosen so that:

 - n is an integer or not, between 2 and 10 inclusive;

 p is an integer or not between 3 and 20 inclusive;

 q is an integer or not between 0 and 30 inclusive.

May in particular be used, alone or in mixtures or associations:

 Nonionic surfactants of the fatty acid or ester type such as, for example, esters, glycol esters, glycerol esters, PEG esters, sorbitol esters, ethoxylated sorbitol esters, ethoxylated acids, or ethoxy propoxylates, esters and triglycerides ( Alkamuls® family of RHODIA, for example ethoxylated hydrocarbon oils: Alkamuls® OR 36 (HLB = 13.1), Alkamuls® RC (HLB 10.5), Alkamuls® R81 (HLB = 9.2) Alkamuls® 696 (HLB 8.2), ethoxylated and / or propoxylated sorbitan esters Alkamuls® T20 or T80.

 Ethoxylated alcoholic or propoxylated ethoxylated nonionic surfactants, such as the Rhodasurf® family of RHODIA, for example Rhodasurf® LA / 30 (HLB = 8), Rhodasurf® ID5 (HLB) = 10.5), Rhodasurf® 860P (HLB = 12.4)),

Ethoxylated aromatic or ethoxylated propoxylated nonionic surfactants, for example the RHODIA Igepal® family,

 Copolymers, copolymers with ethoxy or propoxylated ethoxy blocks, for example the family of Antarox® from Rhodia, such as Antarox® B848 (HLB = 13.1), Antarox® PLG 254 (HLB = 10), Antarox® PL 122 (HLB) = 5),

Styryl phenol-based compounds such as Distyrylphenol, Tristyrylphenol, which may be ethoxylated or ethoxylated propoxylated, phosphated, sulphated, for example the Soprophor® family of RHODIA such as Soprophor® DSS7, Soprophor® BSU (HLB = 12.6), Soprophor 3D33 (HLB = 16), Soprophor 4D384 (HLB = 16), Soprophor® 796P (HLB = 13.7),

 Surfactants derived from terpenes, for example the family Rhodoclean® from RHODIA. e) Other additives

 The dispersion may comprise other additives. It can include:

e1) anti-foam products, for example of the polyorganosiloxane type

e2) humectants, other than glycerol or light polyethylene

e3) bioactivating agents, for example surfactants other than the nonionic surfactant (s), for example amphoteric, zwitterionic or anionic surfactants, e4) fertilizers,

e5) pH regulating agents

e6) thickeners, for example silica or organic polymers other than polyethylene glycol and water-soluble polymer,

e7) oils or oil derivatives such as methyl esters of fatty acids, e8) solvents

e9) ammonium sulphate

 These may be mixtures or combinations of such additives.

It is mentioned that certain additives can fulfill many of the functions mentioned above.

 According to one embodiment, the dispersion comprises at most 200 parts, preferably at most 100 parts, preferably at most 50 parts, preferably at most 25 parts, additives other e).

 According to a particular embodiment, the ratio by weight of e) and the sum of the amounts by weight of a), b), c) and d) is less than 1, preferably less than 0.5, preferably less than 0. 25. Specific characteristics

The dispersion of the invention is typically intended to be diluted with water and / or other products. It is typically intended to be associated with other products, including phytosanitary assets. The dispersion is typically a concentrated ingredient of a final composition or formulation for direct use. Indeed, the formulation industries use ingredients or additives to form mixtures. When an ingredient or additive is mixed with other additives to form a final product, its concentration decreases. Similarly when a ingredient or additive is mixed with water for use in appropriate concentration it sees its concentration decrease. Thus one can speak of "concentrated ingredients", before use by the formulator to form a final product or before dilution by the user for final use without intermediate formulation step. The ingredients or additives may be of different shapes or different compositions to make them practical or to provide particular properties. Some concentrated ingredients are themselves mixtures ("blend" in English). We can talk about complex concentrated ingredients. The dispersion of the invention constitutes such a complex concentrated ingredient.

 Thus, typically the dispersion of the invention comprises a limited quantity of other products (or does not include others).

Preparation process

 The dispersion can be prepared by any suitable method, by mixing the different ingredients. Mixing can be carried out using any appropriate device allowing some agitation. The mixture is generally stirred to obtain a homogeneous mixture.

The process preferably comprises a step where the heavy polyethylene glycol is brought to a temperature above its melting point, for example at a

temperature greater than or equal to 50 ° C. The polyethylene glycol may be brought to this temperature alone or in admixture with one or more of the components of the liquid medium, preferably with the light polyethylene and / or the nonionic surfactant.

 The process preferably comprises a quenching step where the heavy polyethylene passes from a temperature above its melting point to a lower temperature, in the presence of one or more of the components of the liquid medium at a temperature below the melting temperature of the Heavy PEG, preferably with light polyethylene and / or nonionic surfactant. The quenching may in particular be carried out by mixing with one of the components of the liquid medium, preferably with the nonionic surfactant. It can be followed by a gradual cooling.

 During quenching and / or cooling the heavy polyethylene glycol can solidify in the form of often semi-crystalline particles, for example in the form of needles creating a network structuring the liquid medium (or at least the components of the liquid medium already mixed ). The quenching temperature and / or the speed of

The cooling may be controlled to promote formation of the heavy polyethylene particles and / or to control their size and / or morphology so as to provide good stability of the final dispersion. Preferably, the liquid medium is prepared during a step, and the water-soluble polymer, in the form of a powder, is generally added to the liquid medium. During this addition, the liquid medium may already contain the heavy polyethylene glycol. The particle size of the added powder is typically the same as that mentioned above (particle size). According to a preferred embodiment, the polymer

water-soluble is mixed cold after the quenching step mentioned above.

 The other additives can be introduced at any time, preferably after the introduction of the water-soluble polymer. uses

 The dispersion of the invention can be used as an extemporaneous adjuvant of a dilute phytosanitary composition intended to be applied on a field. As such, the dispersion can be introduced into a container, typically a tank or a tank so as to be diluted with water and optionally with other ingredients, including a phytosanitary active product or a formulation comprising such a product. The dilution may typically be 1 part dispersion for 50 to 500 parts water. It is typically operated by the farmer. According to one embodiment, the dispersion is first diluted by pouring it into water and then the active product or the formulation comprising it is added.

 The diluted composition (including the dilution water, the dispersion, and optionally the active product) is then spread over the field to be treated.

 Thus, it is possible to implement a method for applying a phytosanitary composition to a field, comprising:

 a step of mixing in a tank of the dispersion according to one of claims 1 to 7, water and at least one phytosanitary product, where appropriate in the form of a concentrated phytosanitary composition, so as to obtain a diluted phytosanitary composition,

 an application step on the field of the diluted phytosanitary composition.

The application can be performed using any suitable device, including spraying devices and / or jets. Devices can for example be placed on the ground, placed on land vehicles such as tractors, or on air vehicles such as airplanes or helicopters. The amount of diluted composition applied can typically be from 10 to 2000 L / Ha, for example from 50 to 200 L / Ha. Depending on the dilution ratio, the amount of water-soluble polymer in the dispersion, and the application rates, typically from 9 to 1800 g / ha, for example from 45 to 180 g / Ha of water-soluble polymer, can be applied. The dispersion can reduce the drift and / or the rebound of the composition during this operation. As such, the dispersion can be used as an anti-drifting adjuvant and / or anti-rebound. It can help to better target treatment and reduce losses. It may thus be possible to reduce the doses of treatment applied.

Other details or advantages of the invention may appear in light of the following examples, without limitation. Examples

 In the examples the letter C designates a comparative example.

In the examples, the protocol below is used for the preparation of the dispersions.

Protocol of preparation

 For a 600 ml composition, PEG 10000 g / mol and PEG 200 g / L were weighed into a 1 liter glass beaker. The mixture is stirred with Rayneri using a deflocculating blade 65 mm in diameter at 250 rpm and heated on a hot plate until complete dissolution of PEG 10000 g / L (60 ° C mixture temperature). ). The heating is then stopped and NOPOL 365 is added all at once, with stirring and at room temperature to the preceding mixture. The stirring is then increased to 600 rpm, the thickening mixture during its cooling (solidification of PEG 10000 g / L). When the temperature of the mixture has dropped below 30 ° C, the Jaguar® HP-120 is added in rain, still under strong agitation (600 rpm). The antifoam, as well as the silica when necessary, are added with stirring at the end of the preparation.

Example 1

The following dispersions are carried out according to the protocol (the quantities are indicated by weight of material as is):

 An ethoxylated and propoxylated terpene surfactant whose terpene group corresponds to

Nopol, with 3 PO patterns and 6.5 EO patterns, available on request from Rhodia.

As detailed in the following characterization tests, the dispersions have good stability, good flowability, and easy dispersion and hydration in water.

Characterization tests

To evaluate the stability of the formulation and its ease of implementation, the following characteristics are measured after 24 hours of rest and after two months of storage at ambient temperature and in an oven at 45 ° C (CIPAC method MT 46.1 .3 and method GIFAP n ° 17)

The detailed results are as follows

In all cases, the re-homogenization of the formulation when there has been syneresis is easy (2 to 8 bottle inversions).

Example 2 (Comparative)

The following comparative dispersions are carried out according to the same protocol.

Claims

1. Dispersion of particles of a water-soluble polymer in a non-aqueous liquid medium, comprising: a) from 0 to 10 parts of water b) from 1 to 20 parts, preferably from 5 to 15 parts of a water-soluble polymer c) from 0.5 to 5 parts, preferably from 1 to 3 parts, of a heavy polyethylene glycol, with an average molar mass greater than or equal to 6000 g / mol and preferably less than or equal to 500000 g / mol, d) from 80 to 99 parts, of a liquid medium comprising:  d1) optionally a light polyethylene glycol of average molar mass less than or equal to 1000 g / mol, alone or mixed with up to 20% by weight of glycerol  d2) a nonionic surfactant, preferably ethoxylated and / or propoxylated  the ratio by weight between d2) and d1), if d1) is present, being 1/2 to 99/1, preferably 40/60 to 80/20. e) optionally other additives. 2. Dispersion according to one of the preceding claims, characterized in that the water-soluble polymer is an anti-drift and / or anti-rebound polymer. 3. Dispersion according to one of the preceding claims, characterized in that the polymer is a guar optionally chemically modified. 4. Dispersion according to one of the preceding claims, characterized in that the polymer is a guar modified with hydroxyalkyl groups, preferably hydroxypropyl or hydroxybutyl. 5. Dispersion according to one of the preceding claims, characterized in that the nonionic surfactant is an ethoxylated terpene and / or propoxylated. 6. Dispersion according to one of the preceding claims, characterized in that the weight ratio of e) and the sum of the amounts by weight of a), b), c) and d) is less than 1. 7. Dispersion according to one of the preceding claims, characterized in that the additives e) are chosen from: e1) anti-foam products, e2) humectants, different from glycerol or light polyethylene, e3) bioactivating agents, e4) fertilizers, e5) pH regulating agents, e6) thickeners, e7) oils or oil derivatives, e8) solvents e9) ammonium sulfate. 8. Process for preparing the dispersion according to one of the preceding claims, characterized in that it comprises a step wherein the heavy polyethylene glycol is heated to a temperature above its melting point. 9. Method according to the preceding claim, characterized in that it comprises a quenching step where the heavy polyethylene goes from a temperature above its melting point to a lower temperature, in the presence of one or more of the components of the medium. liquid. 10. Use of a dispersion according to one of claims 1 to 7 as an extemporaneous adjuvant of a diluted phytosanitary composition intended to be applied on a field. 1. Use according to claim 10 as anti-drifting and / or debouncing adjuvant. 12. A method of applying a phytosanitary composition to a field, comprising a step of mixing in a tank of the dispersion according to one of claims 1 to 7, water and at least one phytosanitary product, where appropriate in the form of a concentrated phytosanitary composition, so as to obtain a diluted phytosanitary composition,  an application step on the field of the diluted phytosanitary composition.